The invention relates to a fourth generation alcohol-free additive not additionally added in suede preparation of monocrystalline silicon. The fourth generation alcohol-free additive comprises the following main components: a dispersing agent, a humectant and deionized water, wherein the dispersing agent is one of or a combination of more of styrene sodium sulfonate, benzyl naphthalenesulfonate formaldehyde condensate, sodium polyaluminate, sodium hexametahposphate, sodium methylene dinaphthalenesulfonate, sodium polysilicate, sodium lignin sulfonate and sodium polyacrylate; and the humectant is one of or a combination of more of sodium hyaluronate, D5-panthenol, glycerol, propanediol, polyethylene glycol, polypropylene glycol, honey and collagen. When the suede preparation additive is added into a suede preparation solution, clean and uniform monocrystalline silicon suede can be quickly prepared, the photoelectric conversion rate is improved, the production cost is reduced, and the environmental pollution is reduced.